Vehicle seat substructure with an accident-induced adjustment device

ABSTRACT

A vehicle seat substructure has an accident-induced adjustment device including a pair of seat rails having a seat top rail arranged displaceably in relation to a seat bottom rail, and a seat structure arranged pivotably on the seat top rail via a fitting element. The vehicle seat substructure reliably permits the vehicle seat to be fixed along the pair of seat rails in the event of an accident and prevents lowering of the vehicle seat due to forces caused by the accident. The construction is simple to mount and cost-effective to produce and at the same time has little susceptibility to failure and can also be installed completely below any vehicle seat. The fitting element, on the seat top rail and on the seat structure, has a fixing element arranged on the fitting element that passes into a locking position locking the seat top rail to the seat bottom rail.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a United States National Phase Application ofInternational Application PCT/EP2014/061979 filed Jun. 10, 2014 andclaims the benefit of priority under 35 U.S.C. §119 of German PatentApplication 10 2013 106 250.4 filed Jun. 14, 2013 the entire contents ofwhich are incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a vehicle seat substructure having anaccident-induced adjustment device, comprising

-   -   a pair of seat rails having an upper seat rail arranged in a        displaceable manner with respect to a lower seat rail, and    -   a seat structure that is arranged on the upper seat rail in a        pivotable manner via a fitting element.

BACKGROUND OF THE INVENTION

Vehicle seat substructures of the type mentioned at the beginning areknown in a wide variety of configurations from the prior art and areused for the adjustable, in particular vertically adjustable, pivotableand/or displaceable arrangement of a vehicle seat on a vehiclestructure.

A purpose of such a vehicle seat substructure can be to compensate atleast partially for the forces that act on the vehicle seat in the eventof a traffic accident or to bring the vehicle seat into a position inwhich the risk of injury to a passenger sitting on the vehicle seat isreduced to the best possible extent, for which reason it is generally atthe same time desired to secure the position of the vehicle seat withrespect to the vehicle structure.

To this end, known prior art devices use in particular mechanisms whichhave a hook arranged on the vehicle seat, said hook being intended tointeract with a pin arranged on a lower seat rail of a pair of seatrails or of the vehicle structure. However, these devices have thedisadvantage that, until the hook engages with the pin, in particulardepending on the particular adjustment of the vehicle seat on a pair ofseat rails arranged therebeneath, the vehicle seat is initiallyaccelerated considerably and subsequently stopped abruptly by thecontact between the hook and pin, with the result that the risk ofinjury for a passenger arises again. Furthermore, such a catching systemis only reliable to a limited extent, in particular when, in the eventof a traffic accident, forces in different spatial directions occur.

In addition to such a catching system which secures the vehicle seatwith respect to the vehicle structure, an additional mechanism whichprevents the vehicle seat from being pivoted backward on account offorces that arise as a result of an accident is usually required. Tothis end, it is known, in particular from the prior art, to arrangebearing surfaces laterally on the vehicle seat, said bearing surfacescoming into contact with a surface of the pair of seat rails arrangedlaterally next to the vehicle seat in the event of the vehicle seatbeing pivoted backward as a result of an accident, and in the processpreventing further pivoting beyond the surface of the pair of seatrails. However, such a device has the disadvantage that in this case thepair of seat rails absolutely has to be arranged to the side of thevehicle seat, or all of the components of the vehicle seat and of thevehicle seat substructure have to be manufactured in a mannercoordinated with one another, with the result that series production ofa standardized vehicle seat substructure for different vehicle seats isno longer possible.

SUMMARY OF THE INVENTION

An Therefore, the invention is based on the object of providing avehicle seat substructure which makes it possible to reliably fix avehicle seat along a pair of seat rails in the event of an accident andat the same time easily prevents the vehicle seat from dropping onaccount of accident-related forces, wherein the construction is easy toassemble and cost-effective to produce, at the same time has littlesusceptibility to faults and in the process can also be installedentirely beneath any desired vehicle seat.

The vehicle seat substructure according to the invention has anaccident-induced adjustment device comprises a pair of seat railscomprising an upper seat rail arranged in a displaceable manner withrespect to a lower seat rail, and a seat structure that is arranged onthe upper seat rail in a pivotable manner via a fitting element. Thefitting element is configured and arranged on the upper seat rail and onthe seat structure such that, in the event of an accident, a fixingelement arranged on the fitting element passes into a locking positionlocking the upper seat rail to the lower seat rail.

As a result of the arrangement of a fixing element on the fittingelement that is pivotable with respect to the upper seat rail and to theseat structure, the upper seat rail is secured with respect to the lowerseat rail in a particularly simple manner and at the same time furtherdropping of the seat structure connected to the fitting element beyondthe contact of the fixing element with the pair of seat rails iseffectively prevented, wherein a technically complex modification to theconstruction of the fitting element or of the pair of seat rails is notnecessary, with the result that the vehicle seat substructure accordingto the invention can be produced in a particularly cost-effective mannerand can be mounted particularly easily. In addition, the low number ofstructural elements of the vehicle seat substructure according to theinvention advantageously results in low susceptibility to faults.Finally, the arrangement of the fixing element on the fitting elementconnected to the seat structure and the upper seat rail makes itpossible for the pair of seat rails not to be arranged only to the sideof the seat structure, as in known prior art devices, but alsotherebeneath, wherein the action of the fixing element continues to beensured in an unrestricted manner.

In principle, the vehicle seat substructure can be formed from anydesired number of components and have any desired functions. In thiscase, a vehicle seat substructure is initially understood to mean anyconstruction which is originally formed to be arranged under a vehicleseat. Preferably, the seat substructure is in this case formed as amultipart assembly made of metal, for instance steel or aluminum,plastics material, a composite material and/or a fiber-reinforcedmaterial.

In particular, the vehicle seat substructure according to the inventionhas an accident-induced adjustment device, wherein the adjustment devicecan be intended in principle to adjust a vehicle seat arranged on theseat substructure in translation and/or rotation about one or more axesor in one or more spatial directions.

The adjustment device allows at least one pivoting movement of thevehicle seat with respect to a vehicle structure, wherein the adjustmentdevice can be constructed both in such a way that pivoting only takesplace on account of the forces that arise in the event of a trafficaccident, and in such a way that pivoting can additionally also takeplace by way of a user intervention.

In this case, the vehicle seat substructure according to the inventionhas at least one pair of seat rails formed from an upper seat rail and alower seat rail, wherein the two seat rails can be displaced at least inone spatial direction with respect to one another. Preferably, thedisplacement of the seat rails with respect to one another takes placeon a straight path; however, a curved course of the pair of seat railsis also conceivable. The lower seat rail is preferably connected fixedlyto the vehicle structure, while the upper seat rail is arranged on theseat structure directly or via further components. Preferably, a pair ofseat rails is arranged on each side of the vehicle seat.

In this case, the pair of seat rails can in principle consist of anydesired material, for instance a metal, a plastics material or acomposite material, have as many components as desired and fulfillfunctions that go beyond displacement of the upper seat rail withrespect to the lower seat rail. Preferably, however, the upper seat railand/or the lower seat rail are formed integrally.

In this connection, the seat structure is understood to mean at leastthe components of the vehicle seat which provide the vehicle seat with astructure, in particular a seat and/or backrest frame and associatedsupporting and/or cushion elements. Furthermore, the seat structure canalso be formed for example from an integral or multipart shell and/orcomprise armrests, a headrest, safety devices such as airbags or beltelements and further added parts.

Similarly, the vehicle structure is understood to mean the components ofa vehicle which constitute at least the basic structure of the vehicle,in particular the body and/or the vehicle frame.

The vehicle seat substructure according to the invention furthermore hasat least one fitting element which is arranged in a pivotable manner onthe upper seat rail and/or on the seat structure. In this case, thefitting element can in principle be an integral component or an assemblyof as many components as desired. The fitting element is in this caseformed from materials that are known in vehicle construction, inparticular metal, plastics material or a composite material and canfulfill further functions that go beyond the pivotable arrangement ofthe seat structure on the upper seat rail. In the case of a parallelarrangement of two pairs of seat rails as part of the vehicle seatsubstructure, at least one pivotable fitting element is preferablyarranged on each of the two upper seat rails.

Finally, the vehicle seat substructure according to the inventioncomprises a fixing element which is arranged on the fitting element oris formed integrally therewith. In this case, the fixing element caninitially be formed from any desired material, and preferably is formedfrom a hard, deformation-resistant material, for instance a metal, inparticular steel, or a composite material, for instance fiber-reinforcedplastics material. Preferably, the fixing element is formed as a web oras an edge protruding from the fitting element.

According to an advantageous development of the invention, the fixingelement is configured such that, in the locking position, it secures theupper seat rail to the lower seat rail in a force-fitting manner, withthe result that further movement of the upper seat rail with respect tothe lower seat rail is prevented in a particularly simple manner.

According to a further advantageous development of the invention, in thelocking position, the fixing element is arranged in a clamping mannerbetween the upper seat rail and the lower seat rail, wherein, at thetransition into the locking positions, the fixing element preferablypasses between two surfaces, guided on one another, of the lower seatrail and the upper seat rail, thereby achieving reliable, force-fittingsecuring.

According to a preferred configuration of the vehicle seat substructureaccording to the invention, in the locking position, the fixing elementdeforms at least a part of the lower seat rail, preferably at the sametime also a part of the upper seat rail. In particular, securing takesplace by way of irreversible deformation of the lower seat rail and/orof the upper seat rail, with the result that particularly stable, atleast partially also form-fitting securing is achieved in a simplemanner, and also, as a result of the deformation of the components, theforces that act on the vehicle seat in the event of a traffic accidentare already partially dissipated and thus the risk of injury to apassenger on the vehicle seat is reduced.

According to an advantageous development of the invention, the fittingelement is formed in two parts, wherein the fitting element preferablycomprises at least one fitting part and a toothed wheel segment. Atwo-part configuration of the fitting element makes it possible to formthat part of the fitting element that has to withstand particularly highloads or, on account of particularly high forces acting on thecomponent, is subjected to increased wear, from a particularlyhigh-performance material, while the remaining part of the fittingelement can be formed from a conventional and thus cost-effectivematerial.

In this case, a toothed wheel segment is initially understood to mean inprinciple any component which has a plurality of teeth arranged next toone another, wherein the teeth can be arranged both along a circular arcsegment and in any other desired manner. Preferably, the toothed wheelsegment has a plurality of teeth arranged along a circular arc,preferably in an arc segment of between 10° and 45°, and is formed froma particularly abrasion-resistant material, in particular ahigh-strength metal.

In addition to secure and controlled guidance by means of the meshing ofthe toothed wheel segment with a further toothed component, the toothedwheel segment can also fulfill further functions. These include forexample the reinforcement of a region of the fitting element in whichsaid fitting element is arranged on the upper seat rail and/or on theseat structure, wherein such reinforcement can take place in particulararound a part of the circumference or the entire circumference of anopening in the fitting element in order to receive an axle, a pin, ashaft or some other fastening means for pivotable arrangement.

According to a preferred configuration of the invention, the fixingelement is formed integrally with the fitting element, preferablyintegrally with the fitting part of the fitting element, with the resultthat particularly simple and cost-effective production is possible andat the same time the simple structure ensures high functionalreliability.

According to an advantageous development of the invention, the toothedwheel segment is arranged fixedly on the fitting part and interacts witha further component of the vehicle seat such that it is possible toadjust the height or inclination of the vehicle seat with respect to thelower seat rail by means of the fitting element.

In this case, the toothed wheel segment can be connected to the fittingpart of the fitting element in any desired manner, wherein preferablythe toothed wheel segment bears flatly against a part of the fittingpart at least in portions. A force-fitting and/or cohesive and/orform-fitting connection, for instance by adhesive bonding, welding orhot soldering, by means of a fastening means such as a rivet, a pin, ascrew, a bolt or in some other way, is conceivable for connecting thetwo parts.

According to a particularly preferred embodiment of the vehicle seatsubstructure according to the invention, the fitting element, inparticular the fitting part of the fitting element, is formed as astructural element which is angled at least twice, wherein one of theangled parts of the fitting element forms the fixing element, with theresult that the fixing element is connected to the fitting element in aparticularly stable and inseparable manner and thus ensures highfunctional reliability. In this case, both a portion of the fittingelement and the fitting element can be angled over the entire width,wherein both angling twice at right angles in opposite directions andangling twice at any desired angle in the same direction is conceivable.The fixing element is in this case preferably formed as a straight,non-angled component which particularly preferably has a planar outerface on both sides.

Very particularly preferably, the fitting element is angled twice suchthat, in the locking position, a first angled face of the fittingelement passes as the fixing element between the upper seat rail andlower seat rail, while a second angled face comes into contact at leastpartially, preferably contiguously, with a surface of one of the twoseat rails, preferably the upper seat rail.

According to an advantageous development of the invention, the fittingelement is arranged so as to be pivotable in each case both with respectto the upper seat rail and with respect to the seat structure, whereinthe fitting element is preferably connected to the seat structure via anaxle which extends in particular in the seat transverse direction, itthen being possible in a particularly easy manner to arrange the pair ofseat rails entirely beneath the seat structure.

In this way, a vehicle seat, in particular a motor vehicle seat, havinga vehicle seat substructure according to the invention preferably has atleast one pair of seat rails arranged entirely beneath a seat surface ofthe vehicle seat such that the seat structure, in particular a seatframe of the seat surface, is located entirely above the pair of seatrails with respect to the installation position of the vehicle seat in amotor vehicle, even with the fixing element in the locking position,with the result that the vehicle seat structure can have any desiredshape without the functionalities of the vehicle seat substructure andin particular the accident-induced adjustment device being impaired.

A number of exemplary embodiments of the invention are explained in moredetail in the following text with reference to the drawings. The variousfeatures of novelty which characterize the invention are pointed outwith particularity in the claims annexed to and forming a part of thisdisclosure. For a better understanding of the invention, its operatingadvantages and specific objects attained by its uses, reference is madeto the accompanying drawings and descriptive matter in which preferredembodiments of the invention are illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a perspective illustration of a detail of a first embodimentof a vehicle seat substructure;

FIG. 2 is a rotated perspective illustration of the exemplaryembodiment, illustrated in FIG. 1, of the vehicle seat substructure;

FIG. 3 is a perspective illustration of a general view of theembodiment, illustrated in FIG. 1, of the vehicle seat substructure;

FIG. 4 is a perspective illustration from two viewing directions of afitting element of the embodiment, illustrated in FIG. 1, of the vehicleseat substructure with the fixing element arranged thereon;

FIG. 5 is a series of perspective illustrations of a detail of theembodiment, illustrated in FIG. 1, of the vehicle seat substructure inchronological sequence during the transition of the fitting element intoa locking position;

FIG. 6 is a perspective illustration from two viewing directions of afitting element of a second embodiment of the vehicle seat substructure;and

FIG. 7 is a schematic view of a detail of a vehicle seat having a pairof seat rails, arranged entirely beneath a seat surface of a vehicleseat, of the vehicle seat substructure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first embodiment of a vehicle seat substructure 1, a detail of whichis illustrated in FIG. 1, has a fitting element 6a which is secured inan articulated manner to an upper seat rail 5 of a pair of seat rails 3on one side and to an axle 12 of a seat structure 7 on the other side.In this case, the fitting element 6 a comprises, on one side, whichfaces a lower seat rail 4 of the pair of seat rails 3, a fixing element8 a in the form of a rectangular web protruding from the surface of thefitting element 6 a.

The fitting element 6 a is formed from two components, a fitting part 9and a toothed wheel segment 10, that are connected cohesively together(FIG. 3), wherein the toothed wheel element 10 interacts with astructural unit 19 arranged fixedly on the seat structure 7 in order todrive the fitting element 6 a or to damp the latter (FIG. 2).

As illustrated in FIG. 3, the entire vehicle seat substructure 1 has twopairs of seat rails 3 arranged parallel to one another on each of thetwo sides of the seat structure 7, said pairs of seat rails eachcomprising a lower seat rail 4 arranged fixedly on a vehicle structureand an upper seat rail 5 arranged displaceably on said lower seat rail4. The seat structure 7 is arranged above the two pairs of seat rails 3by means of a total of four fittings 6 a, 18, wherein the two fittingelements 6 a located on the rear side of the vehicle seat are arrangedin an articulated manner both on the upper seat rail 5 and on thevehicle structure 7, while the front fittings 18 are connected fixedlyto the upper seat rail 5 and can be pivoted only with respect to theseat structure 7.

The fitting element 6 a formed in two parts comprises a fitting part 9which is formed integrally from sheet metal by stamping and being benttwice. A toothed wheel segment 10 is arranged thereon in a manneroverlapping a part of the surface of the fitting part 9, said toothedwheel segment 10 protruding beyond the surface of the fitting part 9 atleast in the region of its toothing 20.

In this case, the fitting part 9 has a cutout 16 for receiving afastening means on the upper seat rail 5, and an axle receiving opening17 for arranging on an axle 12 connected fixedly to the seat structure7, wherein the toothed wheel segment 10 is arranged on the fitting part9 and fastened such that an opening likewise integrally formed thereonand identical to the axle receiving opening 17 of the fitting part 9comes to lie congruently over said axle receiving opening 17 (FIG. 4).

The toothed wheel segment 10 is formed from a much stronger material,for example a steel, than the fitting part 9, which can consist of sheetmetal.

Pivoting of the fitting element 6 a in the event of a traffic accidentis illustrated in chronological sequence in the depictions in FIG. 5. Inthis case, in the regular use position of the fitting element 6 a, thefixing element 8 a arranged on the latter and the pair of seat rails 3are spaced apart from one another. On account of the forces that occurin the event of a traffic accident, a part, facing the rear side of thevehicle, of the seat structure 7 is lowered by pivoting of the fittingelement 6 a such that the fixing element 8 a passes into a gap betweenthe lower seat rail 4 and upper seat rail 5, wherein it irreversiblydeforms the two seat rails 4, 5 and as a result secures the upper seatrail 5 with respect to the lower seat rail 4.

A fitting element 6 b of a second embodiment of a vehicle seatsubstructure 1 differs from the fitting element 6 a of the firstembodiment of a vehicle seat substructure 1 in that the fitting part 9does not extend in a manner angled at least twice in the same spatialdirection (FIG. 4), but is initially bent approximately at a right anglein one direction and then extends likewise in a manner curvedapproximately at a right angle in the opposite direction (FIG. 6), withthe result that the lower edge of the fitting element 6 b, said loweredge adjoining the cutout 16 for arranging on the upper seat rail 5, canalready be used as a fixing element 8 b, without having to be speciallyshaped further.

The fitting elements 6 a, 6 b of both the first embodiment (FIG. 4) andthe second embodiment (FIG. 6) in this case have, on account of beingangled twice in each case, a planar surface portion which, when afitting element 6 a, 6 b is mounted on the upper seat rail 5, can bebrought into full contact with the surface of this upper seat rail 5,and thus serves as a stop surface 21 in the event of a traffic accident(FIG. 5).

The stop surface 21 integrally formed on the fitting element 6 a, 6 band the possibility of arranging the fitting element 6 a, 6 b in apivotable manner on an axle 12 fastened to the seat structure 7 make itpossible to arrange one or both of the pairs of seat rails 3 entirelybeneath the seat surface 14 of the vehicle seat 13 (FIG. 7), with theresult that a particularly space-saving design of the vehicle seatsubstructure 1 is possible and also nothing stands in the way of anasymmetrical arrangement of the two pairs of seat rails 3 with respectto the seat frame 15.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

1. A vehicle seat substructure having an accident-induced adjustmentdevice, comprising: a pair of seat rails having an upper seat railarranged in a displaceable manner with respect to a lower seat rail; afitting element; a fixing element arranged on the fitting element; and aseat structure is arranged on the upper seat rail in a pivotable mannervia the fitting element wherein the fitting element is configured andarranged on the upper seat rail and on the seat structure such that, inthe event of an accident, the fixing element, arranged on the fittingelement, passes into a locking position locking the upper seat rail tothe lower seat rail.
 2. The vehicle seat substructure as claimed inclaim 1, wherein the fixing element is configured such that, in thelocking position, the fixing element force fit secures the upper seatrail to the lower seat rail.
 3. The vehicle seat substructure as claimedin claim 1, wherein, in the locking position, the fixing element isarranged clamped between the upper seat rail and the lower seat rail. 4.The vehicle seat substructure as claimed in claim 1, wherein, in thelocking position, the fixing element deforms at least a part of thelower seat rail, and also deforms at least a part of the upper seatrail.
 5. The vehicle seat substructure as claimed in claim 1, whereinthe fitting element is formed in at least two parts, wherein the fittingelement comprises at least one fitting part and a toothed wheel segment.6. The vehicle seat substructure as claimed in claim 1, wherein thefixing element is formed integrally with the fitting part of the fittingelement.
 7. The vehicle seat substructure as claimed in claim 1, whereinthe toothed wheel segment is arranged fixedly on the fitting part andinteracts with a further structural unit of the vehicle seat such thatit is possible to adjust the height or inclination of the vehicle seatwith respect to the lower seat rail by means of the fitting element. 8.The vehicle seat substructure as claimed in claim 1, wherein the fittingpart of the fitting element is formed as a structural element which isangled at least twice, wherein one of angled parts of the fittingelement forms the fixing element.
 9. The vehicle seat substructure asclaimed in claim 1, further comprising an axle wherein the fittingelement is arranged so as to be pivotable in each case with respect tothe upper seat rail and with respect to the seat structure, wherein thefitting element connected to the seat structure via the axle.
 10. Amotor vehicle seat comprising a vehicle seat substructure having anaccident-induced adjustment device comprising: a pair of seat railshaving an upper seat rail arranged in a displaceable manner with respectto a lower seat rail; a fitting element; a fixing element arranged onthe fitting element; and a seat structure arranged on the upper seatrail in a pivotable manner via the fitting element wherein the fittingelement is configured and arranged on the upper seat rail and on theseat structure such that, in the event of an accident, the fixingelement, arranged on the fitting element, passes into a locking positionlocking the upper seat rail to the lower seat rail.
 11. The vehicle seatas claimed in claim 10, wherein: the seat structure comprises a seatframe; and at least one pair of seat rails is arranged entirely beneatha seat surface of the vehicle seat such that the seat frame of the seatsurface, is located entirely above the pair of seat rails with respectto the installation position of the vehicle seat in a motor vehicle,even with the fixing element in the locking position.
 12. The vehicleseat as claimed in claim 11, wherein the fixing element is configuredsuch that, in the locking position, the fixing element force fit securesthe upper seat rail to the lower seat rail.
 13. The vehicle seat asclaimed in claim 11, wherein, in the locking position, the fixingelement is arranged clamped between the upper seat rail and the lowerseat rail.
 14. The vehicle seat as claimed in claim 11, wherein, in thelocking position, the fixing element deforms at least a part of thelower seat rail and also deforms at least a part of the upper seat rail.15. The vehicle seat as claimed in claim 11, wherein the fitting elementcomprises at least one fitting part and a toothed wheel segment.
 16. Thevehicle seat as claimed in claim 11, wherein the fixing element isformed integrally with the fitting part of the fitting element.
 17. Thevehicle seat as claimed in claim 11, wherein the toothed wheel segmentis arranged fixedly on the fitting part and interacts with a furtherstructural unit of the vehicle seat such that it is possible to adjustthe height or inclination of the vehicle seat with respect to the lowerseat rail by means of the fitting element.
 18. The vehicle seat asclaimed in claim 11, wherein the fitting element, in particular thefitting part of the fitting element is formed as a structural elementwhich is angled at least twice, wherein one of the angled parts of thefitting element forms the fixing element.
 19. The vehicle seat asclaimed in claim 11, further comprising an axle wherein the fittingelement is arranged so as to be pivotable in each case with respect tothe upper seat rail and with respect to the seat structure, wherein thefitting element connected to the seat structure via the axle.